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oe1(光电查) - 科学论文

2 条数据
?? 中文（中国） ▾

  • “Turn off-on” fluorescent sensor based on quantum dots and self-assembled porphyrin for rapid detection of ochratoxin A

    摘要： We report herein a “turn off-on” fluorescent sensor based on ZnCdSe quantum dots (ZnCdSe QDs) and self-assembled zinc porphyrin for sensitive and rapid detection of ochratoxin A (OTA). Using environmentally friendly dodecyl dimethyl betaine as “soft template”, zinc 5, 10, 15, 20-tetra(4-pyridyl)-21H-23H-porphine (ZnTPyP) was self-assembled into nanorods (SA-ZnTPyP) through a green process. The OTA detection process involves two steps: (1) the fluorescence of ZnCdSe QDs is significantly quenched by SA-ZnTPyP, and (2) the combination between SA-ZnTPyP and OTA releases ZnCdSe QDs from their quenchers such that the fluorescence is recovered. Under the optimized experimental conditions, the newly developed fluorescent sensor showed a linear response in concentration range 0.5–80 ng mL?1, with a detection limit of 0.33 ng mL?1. The excellent applicability of the system has been verified in milk and coffee samples, with relative recoveries between 98.33% and 103.70%. The proposed fluorescent sensor exhibits excellent selectivity and high sensitivity, and thus could be a promising tool for on-site determination of OTA in food safety control and environmental monitoring.

    关键词： Turn off-on,Self-assembled zinc porphyrin,Ochratoxin A,Quantum dots

    更新于2025-09-16 10:30:52

  • Fluorometric determination of hydroquinone by using blue emitting N/S/P-codoped carbon dots

    摘要： N/S/P-codoped carbon dots (CDs) are shown to be a viable fluorescent probe in a turn-off-on fluorometric assay for hydroquinone (HQ). The preparation of CDs was carried out using a one-step hydrothermal reaction starting with glyoxal and isocarbophos. The method is based on the formation of ground state complexes between CD and Fe(III) which leads to quenching of blue fluorescence (with excitation/emission peaks at 363/448 nm). On addition of HQ, it will be oxidized by Fe(III) upon which fluorescence recovers. This turn-off-on system can be utilized to quantify HQ. A linear relationship exists between fluorescence recovery and HQ concentration in range between 0.56 and 375 μM. The limit of detection is 0.16 μM. The assay was successfully applied to the determination of HQ in spiked water samples and developer samples.

    关键词： Developer samples,Blue emission,1,4-dihydroxybenzene,Glyoxal,Fluorescence turn-off-on system,Heteroatoms,Carbon dots,Water samples,Hydrothermal reaction,Fe(III)

    更新于2025-09-09 09:28:46